1. Field of the Invention
The invention relates to an electronic control system and method of operation for an automatic motorized gate operator. The invention provides for connection of a plurality of switching safety edges and photo eye obstruction detection systems to control a motorized gate operating unit which has fewer monitored control inputs than the number of monitored edges required in an application.
2. Description of the Related Art
Motorized doors and gates are used for everything from residential garages to industrial moving, rolling or sliding doors and gates. In this disclosure, any reference to the term “gate” or “gate systems” also applies to “door” or “door systems.” For many years, it has been a best practice and frequently a legal safety requirement to provide an obstruction protection mechanism to stop a motorized gate moving along a given track when the gate has an obstruction that will strike the gate if the motor driving the gate is not stopped. Many automatic doors or gates, particularly those such gates used in industry, have a gate operating unit which controls the power to the motor to open or close the motorized gate along its normal path.
The most common devices used to detect obstructions are photo beams and safety edges. Photo beams monitor a continuous path between a light emitter and a light receiver. Constant presence of the light beam between the transmitter and receiver signals no obstruction in the path, and an interrupted beam would indicate an obstruction or possibly failed sensor. It is desirable in monitored systems to recognize either event. Likewise, safety edges are switching devices placed along leading edges of moving doors or gates which change switching states upon obstruction contact to any portion of the switch.
To detect a fault in the switch as a fail-safe requirement, the switch is monitored to confirm continuity of the switch as a closed circuit. Upon activation from contact with an obstruction, the switch changes electrical state. Typical normal state continuity resistance is set to ten thousand ohms (“10KΩ”). Compression of typical edge switches along its length measures a short circuit and an open circuit measurement signals a fault in the edge or the associated wiring.
Monitoring for safety by detecting obstructions in the path of gates or moving doors is not new, but changes in safety regulations or best practices have required new methods of monitoring and an evolution in hardware to do so. There are recent changes in recognized standards for monitoring motorized gates in particular. Underwriters Laboratories® (“UL”) and the American Society for Testing and Materials® (“ASTM”) are the most well know examples of standard promulgating entities that have presented a need to increase monitoring of the number of possible entrapment areas in a moving gate.
A new UL 325 standard is a safety standard for door, drapery, gate, louver, and window operators and systems. Specifically, it applies to electric operators for doors, draperies, gates, louvers, windows and other opening and closing appliances. Similarly, ASTM F2200 is a standard that pertains to automated vehicular gates. ASTM F2200 recognizes five gate classifications: horizontal slide, horizontal swing, vertical lift, vertical pivot, and overhead pivot. UL325 was updated to require additional obstruction detecting devices for most gate installations. These updates became effective Jan. 12, 2016. The present disclosure relates to a system that addresses a need to interface more edge and obstruction monitoring sensors using existing gate operators which have less sensor inputs than the number of sensor required.
In the case of a garage door, a photo beam can detect the presence of an obstruction near the floor, while a safety edge can detect obstructions anywhere along the path of travel. The entrapment area is always the door opening, and is only of concern when the door is moving in the closing direction. A garage door closing may contact an obstruction or hazard on the way down, closing a switch when contacted the obstruction. Photo eye beams break continuity when the obstruction is present breaking the beam.
Alternately, a gate installation will likely have multiple entrapment areas, each of which may need to be guarded by entrapment protection devices. These entrapment zones may be further complicated as both directions of travel (opening and closing) need to be considered. Examples of the applications to which the invention is applied are found in standards publications such as an application drawing found at DASMA ASTM F2200. In the most complicated case, six entrapment detection devices may be required to guard all of the entrapment zones of a motorized gate.
In motorized, moving gate systems particularly, the direction of travel of the moving gate, laterally in relation to the ground in most instances, requires protecting several different areas around the gate to sense obstructions. Typically both edge sensors and photo eye type sensors are employed. With motorized gates, more than one of each type sensor is needed to protect up to four or five areas, such areas of the gate traveling in a reversible lateral direction. Leading and trailing edges of a gate need be protected and the gate movement area in each instance also need be protected from obstruction before an edge switch might contact an obstruction. Similar situations exist for swing gates and vertical lift gates. An interface device is needed to provide for such multiple inputs from safety edge or obstruction devices protecting a moving or motorized gate.
Accordingly, a device and method is needed in which the user of a motorized gate safety sensing system can use multiple sensor inputs ranging from edge sensing switch devices to photo eye devices commonly used in the industry. A system which allows retrofitting of existing gate operating units which provide for fewer sensor inputs than required for a multi sensor application would be useful. Such a conversion must maintain the safety conditions afforded by monitoring the operational readiness of the several switching edge protection devices while also monitoring multiple photo eye sensors, all controlling the same door operator.
It is the object of the present invention to provide an interface device which will allow a motorized gate operating unit to accept the application of a plurality of edge or area protecting devices without changing or modifying an existing gate operating unit which does not provide for a sufficient number of inputs. The disclosed invention could be used in new installations or to update existing installations.
It is further the object of the present invention to provide a conversion device to allow a motorized gate operator with a limited number of inputs to accept inputs from more device controlling or protecting gate edges in each operational direction by the door operating unit.
It is also the object of the present invention to provide a method of retrofitting an existing installation of a motorized gate or door with obstruction protection having a motor controller with insufficient input ports to accommodate multiple sensor edges and photo-eye type protective devices.
It is a further object of the present invention to accept multiple devices each of which use different signaling technologies and all of which require monitoring without the requirement of changing the controller or applying different power requirements.